Search

Summary Congenital heart surgery is associated with a 2–25% reported incidence of neurological complication. Near-infrared spectroscopy (NIRS) can detect changes in regional cerebral saturation index (rSO2i) during cardiac surgery. If rSO2i decreases significantly, treatment algorithms are used to restore baseline values, potentially avoiding neurological complications. The efficacy of bilateral NIRS monitoring in pediatric congenital heart surgery has been debated. We report a case in which bilateral NIRS monitoring detected an abrupt decrease in rSO2i (right greater than left) after initiation of bypass without abnormalities detected by standard monitors. This resulted in prompt surgical intervention that restored rSO2i, potentially preventing neurological injury.

OBJECTIVE: The purpose of this study was to assess the utility of preoperative head ultrasound scan (HUS) in a cohort of newborns also undergoing preoperative MRI as part of a prospective research study of brain injury in infants having surgery for congenital heart disease (CHD). METHODS: A total of 167 infants diagnosed with CHD were included in this 3-center study. None of the patients had clinical signs or symptoms of preoperative brain injury, and all patients received both HUS and brain MRI before undergoing surgical intervention. HUS and MRI results were reported by experienced neuroradiologists who were blinded to any specific clinical details of the study participants. The findings of the individual imaging modes were compared to evaluate for the presence of brain injury. RESULTS: Preoperative brain injury was present on HUS in 5 infants (3%) and on MRI in 44 infants (26%) ( P < .001). Four of the HUS showed intraventricular hemorrhage not seen on MRI, suggesting false-positive results, and the fifth showed periventricular leukomalacia. The predominant MRI abnormality was white matter injury ( n = 32). Other findings included infarct ( n = 16) and hemorrhage ( n = 5). CONCLUSIONS: Preoperative brain injury on MRI was present in 26% of infants with CHD, but only 3% had any evidence of brain injury on HUS. Among positive HUS, 80% were false-positive results. Our findings suggest that routine HUS is not indicated in asymptomatic term or near-term neonates undergoing surgery for CHD, and MRI may be a preferable tool when the assessment of these infants is warranted. * Abbreviations: 2V — : biventricular 2VA — : biventricular with arch obstruction CHD — : congenital heart disease DWI — : diffusion-weighted imaging HUS — : head ultrasound scan IVH — : intraventricular hemorrhage LSV — : lenticulostriate vasculopathy PVL — : periventricular leukomalacia RCH — : Royal Children’s Hospital SCH — : Starship Children’s Hospital SV — : single ventricle SVA — : single ventricle with arch obstruction TCH — : Texas Children’s Hospital WMI — : white matter injury

To summarize recent publications emphasizing the changes in the population of patients with congenital heart disease and trends in the anesthetic and perioperative care of these patients presenting for noncardiac procedures.It has been reported that children with congenital heart disease presenting for noncardiac surgery are at an increased anesthetic risk. This risk has become better defined. The patients at highest risk are infants with a functional single ventricle and patients with suprasystemic pulmonary hypertension, left ventricular outflow tract obstruction or dilated cardiomyopathy. Familiarity with the physiology and perioperative implications of the stages of single ventricle palliation is critical. The anesthetic approach, monitoring, conduct of surgery and postoperative care and outcomes are variable in this patient population. Recent literature reflects the growing number of children with ventricular assist devices and the management of these patients for noncardiac procedures. Cardiac imaging modalities provide diagnostic information, and strategies for reducing anesthetic risk for these procedures are of great interest. Pharmacologic trends and the application of technology are reviewed.The identification of high-risk patients, multidisciplinary decision-making and planning and careful anesthetic management and monitoring are critical for optimizing outcomes in children with congenital heart disease presenting for noncardiac procedures.

New noninvasive methods for monitoring cerebrovascular pressure reactivity coupled with a blood-based assay for brain-specific injury in preterm infants could allow early diagnosis of brain injury and set the stage for improved timing and effectiveness of interventions. Using an adaptation of near-infrared spectroscopy, we report a case of a very low birth weight infant undergoing hemoglobin volume index monitoring as a measure of cerebrovascular pressure reactivity. During the monitoring period, this infant demonstrated significant disturbances in cerebrovascular pressure reactivity that coincided with elevation of serum glial fibrillary acidic protein and new findings of brain injury on head ultrasound. This case report demonstrates the potential of emerging noninvasive monitoring methods to assist in both detection and therapeutic management to improve neurologic outcomes of the very low birth weight neonate.

The pressure reactivity index (PRx) identifies optimal cerebral perfusion pressure after traumatic brain injury. We describe a method to improve PRx precision by induced variations in arterial blood pressure (ABP) using positive end-expiratory pressure (PEEP) modulation ( iPRx). Neonatal swine ( n = 10) were ventilated with static PEEP and then with PEEP oscillated between 5 and 10 cmH2O at a frequency of 1/min. PRx was recorded as a moving correlation coefficient between ABP and intracranial pressure (ICP) from spontaneous ABP activity (0.05-0.003 Hz) during static PEEP. iPRx was similarly recorded with PEEP oscillation-induced ABP waves. The lower limit of autoregulation (LLA) was delineated with continuous cortical laser Doppler flux monitoring. PEEP oscillation increased autoregulation-monitoring precision. The ratios of median absolute deviations to range of possible values for the PRx and iPRx were 9.5% (8.3–13.7%) and 6.2% (4.2–8.7%), respectively ( P = 0.006; median, interquartile range). The phase-angle difference between ABP and ICP above LLA was 161° (150°–166°) and below LLA, −31° (−42° to 12°, P < 0.0001). iPRx above LLA was −0.42 (−0.67 to −0.29) and below LLA, 0.32 (0.22–0.43, P = 0.0004). A positive iPRx was 97% specific and 91% sensitive for perfusion pressure below LLA. PEEP oscillation caused stable, low-frequency ABP oscillations that reduced noise in the PRx. Safe translation of these findings to clinical settings is expected to yield more accurate and rapid delineation of individualized optimal perfusion-pressure goals for patients.

Hypotension and shock are risk factors for death, renal insufficiency, and stroke in preterm neonates. Goal-directed neonatal hemodynamic management lacks end-organ monitoring strategies to assess the adequacy of perfusion. Our aim is to develop a clinically viable, continuous metric of renovascular reactivity to gauge renal perfusion during shock. We present the renovascular reactivity index (RVx), which quantifies passivity of renal blood volume to spontaneous changes in arterial blood pressure. We tested the ability of the RVx to detect reductions in renal blood flow. Hemorrhagic shock was induced in 10 piglets. The RVx was monitored as a correlation between slow waves of arterial blood pressure and relative total hemoglobin (rTHb) obtained with reflectance near-infrared spectroscopy (NIRS) over the kidney. The RVx was compared with laser-Doppler measurements of red blood cell flux, and renal laser-Doppler measurements were compared with cerebral laser-Doppler measurements. Renal blood flow decreased to 75%, 50%, and 25% of baseline at perfusion pressures of 60, 45, and 40 mmHg, respectively, whereas in the brain these decrements occurred at pressures of 30, 25, and 15 mmHg, respectively. The RVx compared favorably to the renal laser-Doppler data. Areas under the receiver operator characteristic curves using renal blood flow thresholds of 50% and 25% of baseline were 0.85 (95% CI, 0.83–0.87) and 0.90 (95% CI, 0.88–0.92). Renovascular autoregulation can be monitored and is impaired in advance of cerebrovascular autoregulation during hemorrhagic shock.

BACKGROUND Autoregulation is impaired by traumatic brain injury. Cerebral blood flow disturbances are spatially heterogeneous, but autoregulation is often reported as a global metric. OBJECTIVE We tested lateralization of autoregulatory responses in the neonatal piglet brain during hypotension early after unilateral injury. METHODS Neonatal piglets (5-7 days old) had controlled cortical impact (severe, n = 12; moderate, n = 13; sham, n = 13) and recovery for 6 hours. The lower limit of autoregulation (LLA) and static rate of autoregulation (SRoR) were determined for each subject and compared among groups and between the ipsilateral and contralateral hemispheres. RESULTS The LLA was not increased by injury (sham, 34 mm Hg [29-39 mm Hg]; moderate injury, 37 mm Hg [33-41 mm Hg]; severe injury, 35 mm Hg [32-38 mm Hg]; P = .93, mean [95% confidence interval]). SRoR, when measured ipsilateral to injury and above the LLA, showed intact autoregulation and was not lower than SRoR in uninjured subjects (sham, 0.82 [0.53-1.1]; moderate injury, 1.0 [0.60-1.5]; severe, 0.91 [0.33-1.5]; P = .44). The average hemispheric LLA difference was 2.7 mm Hg, (95% limits of agreement, -7.5 to 7.0; bias, -0.25; Spearman r = 0.73; P < .0001). Ipsilateral and contralateral SRoR measurements also showed correlation in the injured groups (Spearman r = 0.85, P < .0001). CONCLUSION LLA was not increased by controlled cortical impact, nor did SRoR measurements demonstrate ineffective autoregulation when cerebral perfusion pressure was greater than and within 10 mm Hg of the LLA. Cerebral perfusion pressure optimization, indicated by autoregulation measurements, was significantly similar in the 2 hemispheres despite severe unilateral injury.

Prevention of brain injury during congenital heart surgery has focused on intraoperative and perioperative neuroprotection and neuromonitoring. Many strategies have been adopted as “standard of care.” However, the strength of evidence for these practices and the relationship to long-term outcomes are unknown. We performed a systematic review (January 1, 1990 to July 30, 2010) of neuromonitoring and neuroprotection strategies during cardiopulmonary bypass (CPB) in infants of age 1 year or less. Papers were graded individually and as thematic groups, assigning evidence-based medicine and American College of Cardiology/American Heart Association (ACC/AHA) level of evidence grades. Consensus scores were determined by adjudication. Literature search identified 527 manuscripts; 162 met inclusion criteria. Study designs were prospective observational cohort (53.7%), case-control (21.6%), randomized clinical trial (13%), and retrospective observational cohort (9.9%). Median sample size was 43 (range 3 to 2,481). Primary outcome was evidence of structural brain injury or functional disability (neuroimaging, electroencephalogram, formal neurologic examination, or neurodevelopmental testing) in 43%. Follow-up information was reported in only 29%. The most frequent level of evidence was evidence-based medicine level 4 (33.3%) or ACC/AHA class IIB: level B (42%). The only intervention with sufficient evidence to recommend “the procedure or treatment should be performed” was avoidance of extreme hemodilution during CPB. Data supporting use of current neuromonitoring and neuroprotective techniques are limited. The level of evidence is insufficient to support effectiveness of most of these strategies. Well-designed studies with correlation to clinical outcomes and long-term follow-up are needed to develop guidelines for neuromonitoring and neuroprotection during CPB in infants.

Assessing the depth of sedation in children is critically important to determine whether the goals of sedation are met without exposing the patient to the risk of adverse outcomes. In Cravero’s model of pediatric sedation, the patient’s state ranges from fully awake undergoing a painful procedure without sedation or analgesia to apnea, hypoxia, and death from oversedation. Clearly, having the sedated child’s state in the goal zone is important, and objective tools to assess sedation depth are necessary to standardize depth of sedation. Additionally, having objective assessment scales available to rate a child’s readiness for discharge from a sedation recovery area is also important, as premature discharge may lead to adverse events and even death. This chapter will review commonly used pediatric sedation scales, focusing on procedural sedation. Then methods of sedation assessment using processed EEG will be reviewed and compared to pediatric sedation scales.

Safe sedation of pediatric patients requires a thorough understanding of the physiological differences between infants, children, adolescents, and adults. Especially in small infants, there is much less margin for any errors in diagnosis and treatment of respiratory or cardiovascular depression during sedation procedures. This chapter will review developmental aspects of respiratory, cardiovascular, central nervous system, renal, hepatic, hematologic, and temperature homeostatic systems, highlighting the differences between children and adults and emphasizing their relevance to sedation procedures in children.

Neurological injury still occurs in association with pediatric cardiac surgery, despite major progress in reducing mortality. Forty to 50% of 5 year olds who underwent complex open cardiac surgery as neonates and young infants have impaired neurodevelopmental outcomes. In order to apply neuroprotective strategies, it is necessary to develop markers for acute neurological injury, and surrogates that predict later abnormal neurodevelopmental outcomes. Near infrared spectroscopy holds promise as a marker of acute brain injury, with several pediatric cardiac surgery studies indicating a relationship between prolonged low cerebral oxygen saturation and clinical or MRI change. EEG seizures have not been found to have a relationship with acute or longer term neurological injury in recent studies. Brain MRI indicates that approximately 30% of neonates have MRI injury before cardiac surgery, and 40% have new injury postoperatively, predominately white matter injury. Serum or urine biomarkers, such as S100β protein, neuron–specific enolase, or creatine kinase brain band, lack specificity for nervous system injury. Newer biomarkers, such as glial fibrillary acidic protein, ubiquitin C-terminal hydrolase 1, and phosphorylated axonal neurofilament heavy chain, have potential for much greater specificity. Neuroprotective strategies include cardiopulmonary bypass techniques which avoid circulatory arrest and low flows. Certain anesthetic regimens such as halogenated anesthetic agents, ketamine, and dexmedetomidine may be neuroprotective in pediatric cardiac surgery. Therapeutic hypothermia, and remote ischemic preconditioning are two simple techniques that may prove to have neuroprotective properties. Erythropoietin pretreatment, and treatment with neurotrophic factors such as brain-derived neurotrophic factor, glial cell line derived neurotrophic growth factor, vascular endothelial growth factor, and nerve growth factor also have potential to prevent and treat neuronal loss in the perioperative period. Finally, neural stem cells derived from the patient’s own umbilical cord blood could potentially be utilized for neuroprotection in neonates with a prenatal diagnosis of congenital heart disease.

Objective: To assess the effects of transesophageal echocardiography (TEE) on hemodynamic variables during cardiac surgery in small infants. Design: A prospective clinical study. Setting: A medical college-affiliated tertiary care children's hospital. Participants: Twenty-three infants weighing 2 to 5 kg undergoing cardiac surgery. Interventions: Baseline heart rate, arterial pressure, and central venous pressure were recorded. A pediatric TEE probe was inserted, and the hemodynamic variables were again recorded. Postoperatively the hemodynamic measurements were measured again before and after probe removal, with the addition of left atrial pressure and pulmonary artery pressure when available. Hemodynamic parameters were carefully observed during all phases of the TEE examinations for any changes attributable to probe manipulation. Measurements and Main Results: No statistically significant changes occurred in this group of patients during TEE. No clinically significant changes in any individual patient occurred during the measurement or during manipulation of the TEE probe for the complete examination. Conclusion: Although hemodynamic compromise can occur in small infants, this study suggests that it is infrequent. Fear of hemodynamic compromise should not prevent use of intraoperative TEE in small infants when otherwise indicated.

UNLABELLED Transesophageal echocardiography (TEE) is frequently used during congenital cardiac surgery. Complications are infrequent, but interference with ventilation has been reported, especially in small infants. Ventilation variables were measured prospectively in 22 infants, 2-5 kg, undergoing heart surgery with TEE. Measurements were made preoperatively before and after TEE probe insertion and postoperatively before and after TEE probe removal. The variables measured included arterial blood gases, expired tidal volume, peak inspiratory pressure, positive end-expiratory pressure, minute ventilation, airway resistance, dynamic compliance, and peak inspiratory and expiratory flow rates. No significant change in any ventilatory variable at either time period was noted in the infants. IMPLICATIONS Ventilatory compromise is infrequent in small infants undergoing transesophageal echocardiography (TEE) examination. Careful ventilatory monitoring rapidly detects changes in ventilation during TEE examination. Small infants who benefit from TEE during heart surgery should not be excluded from receiving a TEE examination because of concern of ventilatory compromise.

Despite a relatively universally applicable knowledge base and skill set, training and experience in pediatric cardiac anesthesia in currently organized basic anesthesia and Adult Cardiothoracic Anesthesia fellowship programs are very limited and not uniformly available. Experience during Pediatric Anesthesia fellowship training is uniformly available but of limited duration and varying intensity. We present a schema, developed by a working group of the Congenital Cardiac Anesthesia Society, for training in pediatric cardiac anesthesia that pediatric cardiac anesthesia educators internationally should consider as a template to be modified as necessary.

Antegrade cerebral perfusion (ACP) is a cardiopulmonary bypass technique that uses special cannulation procedures to perfuse only the brain during neonatal and infant aortic arch reconstruction. It is used in lieu of deep hypothermic circulatory arrest (DHCA), and thus has the theoretical advantage of protecting the brain from hypoxic ischemic injury. Despite this, recent comparative studies have shown no difference in neurodevelopmental outcomes with ACP versus DHCA for neonatal arch repair. This article presents animal and human data demonstrating that ACP flows less than 30 mL/kg/min are inadequate for many patients, and may be the explanation for lack of outcome difference versus DHCA. A technique for ACP, its physiologic basis, and a neuromonitoring strategy are presented, and then the results of an outcome study are reviewed, showing that with ACP technique at higher flows of 50 to 80 mL/kg/min guided by neuromonitoring, periventricular leukomalacia is eliminated on postoperative brain magnetic resonance imaging after neonatal cardiac surgery.

Congenital heart disease is a risk factor for the development of necrotizing enterocolitis, although the exact mechanism of development remains unclear. Herein, we report the case of an infant with pulmonary atresia, an intact ventricular septum, and multiple aortopulmonary collateral vessels. At 4 weeks of age, the infant developed necrotizing enterocolitis in association with significant mesenteric oxygen desaturation, as measured by means of near-infrared spectroscopy. With bowel rest and antibiotic therapy, the patient's mesenteric oxygen saturation and clinical status improved. This case highlights the importance of impaired mesenteric oxygen delivery consequential to congenital heart disease as a possible risk factor for necrotizing enterocolitis, and the use of near-infrared spectroscopy to measure tissue perfusion noninvasively in high-risk patients. To our knowledge, this is the 1st report of mesenteric oxyhemoglobin desaturation in association with necrotizing enterocolitis in a patient who also had congenital heart disease.

Near-infrared spectroscopy was used to monitor cerebral and mesenteric regional oximetry in a preterm neonate undergoing surgical ligation of a patent ductus arteriosus. This patient initially demonstrated severe mesenteric oxyhemoglobin desaturation, which improved immediately following ductal ligation.

Summary Background : Infants with tracheoesophageal fistula (TEF) and/or esophageal atresia (EA) frequently have other associated congenital anomalies which can have a significant impact on their anesthetic care and survival to discharge. Methods : A medical record review and retrospective data analysis were performed in a university affiliated children's hospital of all infants undergoing TEF/EA repair between January 1998 and July 2004. The incidence of intraoperative complications during the TEF repair and overall survival to hospital discharge was compared in two groups of infants: 26 patients with TEF/EA and coexisting congenital heart disease (CHD), and 27 patients with TEF/EA and no CHD. Results : The overall incidence of intraoperative critical events during repair of TEF/EA was significantly higher in infants with associated cardiac pathology (P = 0.003). Six of 53 infants died during hospitalization (overall mortality, 11.3%) and all had associated cardiac pathology. In comparison with nonductal-dependent lesions, the presence of a ductal-dependent cardiac lesion appeared to significantly increase patient mortality (57% vs. 10%, P = 0.028). Conclusions : Low birth weight (

For patients with transposition of the great arteries and a systemic right ventricle, complex late arterial-switch operations (double switch, switch conversion, Senning-Rastelli) after the newborn period have been described recently to restore the morphologic left ventricle to the systemic circulation. The purpose of this study was to describe the anesthetic management and perioperative outcome of this group of patients and to compare them with a control group of patients who had primary arterial-switch operations in the neonatal period.Retrospective database and medical record review with 3:1 control:case ratio.Tertiary care academic children's hospital.Patients undergoing complex late-arterial switch operations after the newborn period.None.Thirteen patients were identified in the complex late-switch group and 43 in neonatal arterial-switch group. There were no perioperative deaths, no new gross neurologic deficits, and all patients were discharged home in both groups. Anesthetic and bypass times were significantly longer in the late-switch group (745 v 558 minutes, p0.001, and 382 v 243 minutes, p0.001, respectively). Transfusion requirements were similar between the groups. The incidence of arrhythmia (92% v 9%, p0.001), use of pacing systems (69% v 9%, p0.001), cardioversion (15% v 0%, p = 0.05), and pharmacologic treatment of arrhythmias (69% v 0%, p0.01) intraoperatively were significantly higher in the complex late-switch group.Patients presenting for complex late corrective operations for transposition of the great arteries require long and complex anesthetics. Despite these challenges, perioperative outcomes are excellent.

Background: Near-infrared spectroscopy (NIRS) is a noninvasive optical monitor of regional cerebral oxygen saturation (rSO 2 ). The aim of this study was to validate the use of NIRS by cerebral oximetry in estimating invasively measured mixed venous oxygen saturation (SvO 2 ) in pediatric postoperative cardiac surgery patients. Methods: Twenty patients were enrolled following cardiac surgery with intraoperative placement of a pulmonary artery (PA) or superior vena cava (SVC) catheter. Five patients underwent complete biventricular repair - complete atrioventricular canal (n = 3) and other (n = 2). Fifteen patients with functional single ventricle underwent palliative procedures - bidirectional Glenn (n = 11) and Fontan (n = 4). Cerebral rSO 2 was monitored via NIRS (INVOS 5100) during cardiac surgery and 6 h postoperatively. SvO 2 was measured from blood samples obtained via an indwelling PA or SVC catheter and simultaneously correlated with rSO 2 by NIRS at five time periods: in the operating room after weaning from cardiopulmonary bypass, after sternal closure, and in the CICU at 2, 4, and 6 h after admission. Results: Each patient had five measurements (total = 100 comparisons). SvO 2 obtained via an indwelling PA or SVC catheter for all patients correlated with rSO 2 obtained via NIRS: Pearson's correlation coefficient of 0.67 (P < 0.0001) and linear regression of r2 = 0.45 (P < 0.0001). Separate linear regression of the complete biventricular repairs demonstrated an r = 0.71, r2 = 0.50 (P < 0.0001). BlandAltman analysis showed a bias of +3.3% with a precision of 16.6% for rSO 2 as a predictor of SvO 2 for all patients. Cerebral rSO 2 was a more accurate predictor of SvO 2 in the biventricular repair patients (bias -0.3, precision 11.8%), compared with the bidirectional Glenn and Fontan patients. Conclusions: Regional cerebral oximetry via NIRS correlates with SvO 2 obtained via invasive monitoring. However, the wide limits of agreement suggest that it may not be possible to predict absolute values of SVO 2 for any given patient based solely on the noninvasive measurement of rSO 2 . Near-infrared spectroscopy, using the INVOS 5100 cerebral oximeter, could potentially be used to indicate trends in SVO 2 , but more studies needs to be performed under varying clinical conditions.

Anesthesia for congenital heart disease , Anesthesia for congenital heart disease , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

Anesthesiologists face a dilemma in determining appropriate dosing of anesthetic drugs in obese children. In this study we determined the dose of propofol that caused loss of consciousness in 95% (ED(95)) of obese and nonobese children as determined by loss of eye lash reflex.Forty obese (body mass index [BMI]95th percentile for age and gender) and 40 normal weight (BMI 25th to 84th percentile) healthy ASA 1 to 2 children ages 3 to 17 years presenting for surgical procedures were studied using a biased coin design. The primary endpoint was loss of lash reflex at 20 seconds after propofol administration. The first patient in each group received 1.0 mg/kg of IV propofol, and subsequent patients received predetermined propofol doses based on the lash reflex response in the previous patient. If the lash reflex was present, the next patient received a dose increment of 0.25 mg/kg. If the lash reflex was absent, the next patient was randomized to receive either the same dose (95% probability) or a dose decrement of 0.25 mg/kg (5% probability). The ED(95) and 95% confidence intervals (CI) were calculated using isotonic regression and bootstrapping methods respectively.The ED(95) of propofol for loss of lash reflex was significantly lower in obese pediatric patients (2.0 mg/kg, approximate 95% CI, 1.8 to 2.2 mg/kg) in comparison with nonobese patients (3.2 mg/kg, approximate 95% CI, 2.7 to 3.2 mg/kg), P ≤ 0.05.A simple approach to deciding what dose of propofol should be used for induction of anesthesia in children ages 3 to 17 years is to first establish the child's BMI on readily available gender-specific charts. Obese children (BMI95th percentile for age and gender) require a lower weight-based dose of propofol for induction of anesthesia, than do normal-weight children.

Background Patients with congenital heart disease characterized by a functional single ventricle make up an increasing number of patients presenting for cardiac or noncardiac surgery. Conventional echocardiographic methods to measure left ventricular function, i.e., ejection fraction, are invalid in these patients because of altered ventricular geometry. Two recently described Doppler echocardiographic modalities, the myocardial performance index and Doppler tissue imaging, can be applied to single-ventricle patients because they are independent of ventricular geometry. This study assessed the changes in myocardial performance index and Doppler tissue imaging in response to two anesthetic regimens, fentanyl-midazolam-pancuronium and sevoflurane-pancuronium. Methods Thirty patients aged 4-12 months with a functional single ventricle were randomized to receive fentanyl-midazolam or sevoflurane. Myocardial performance index and Doppler tissue imaging were measured by transthoracic echocardiography at baseline and two clinically relevant dose levels. Results Sixteen patients receiving sevoflurane and 14 receiving fentanyl-midazolam were studied. Myocardial performance index was unchanged from baseline with either agent (fentanyl-midazolam: 0.50 +/- 15 baseline vs. 0.51 +/- 0.15 at dose 2; sevoflurane: 0.42 +/- 0.14 baseline vs. 0.46 +/- 0.09 at dose 2). Doppler tissue imaging S (systolic)- and E (early diastolic)-wave velocities in the lateral ventricular walls at the level of the atrioventricular valve annulus were unchanged in the sevoflurane group; however, both Doppler tissue imaging S- and E-wave velocities were decreased significantly from baseline at dose 1 and dose 2 with fentanyl-midazolam, consistent with decreased longitudinal systolic and diastolic ventricular function. Conclusions Myocardial performance index, a global measurement of combined systolic and diastolic ventricular function, is not affected by commonly used doses of fentanyl-midazolam or sevoflurane in infants with a functional single ventricle.

The incidence of neurological complications after pediatric cardiac surgery ranges from 2% to 25%. The causes are multifactorial and include preoperative brain malformations, perioperative hypoxemia and low cardiac output states, sequelae of cardiopulmonary bypass, and deep hypothermic circulatory arrest. Neurological monitoring devices are readily available and the anesthesiologist can now monitor the brain during pediatric cardiac surgery. In this review we discuss near-infrared cerebral oximetry, transcranial Doppler ultrasound, and electroencephalographic monitors for use during congenital heart surgery. After review of the basic principles of each monitoring modality, we discuss their uses during pediatric heart surgery. We present evidence that multimodal neurological monitoring in conjunction with a treatment algorithm may improve neurological outcome for patients undergoing congenital heart surgery and present one such algorithm.

Deep hypothermic circulatory arrest (DHCA) is commonly used for neonatal cardiac surgery. However, prolonged exposure to DHCA is associated with neurologic morbidity. The Norwood operation and aortic arch advancement are procedures that typically require DHCA during surgical correction. Regional low flow perfusion (RLFP) can be used to limit or exclude the use of circulatory arrest. This technique involves cannulation of the innominate or subclavian artery using a Gore-Tex graft, allowing isolated cerebral perfusion. Data was collected in 34 patients undergoing either neonatal aortic arch reconstruction or the Norwood procedure using RLFP. All patients had two arterial pressure monitors using either the umbilical or femoral artery catheters and radial or brachial catheters. Adequacy of perfusion was determined using cerebral saturation, blood flow velocity, mean arterial pressures, and arterial blood gas results. Cerebral saturation and blood flow velocity were monitored using the near-infrared spectroscopy (NIRS) (INVOS 5100, Somanetics Corp, Troy, MI) and a transcranial Doppler pulse-wave ultrasound (TCD) (EME Companion, Nicolet Biomedical, Madison, WI), respectively throughout the entire bypass period. Blood gases were monitored using a point of care blood gas analyzer (Gem Premier, Mallinckrodt Sensor System, Inc., Ann Arbor, MI). Data collected revealed total bypass times for repair between 69-348 min, with a mean of 180 min. Regional low flow perfusion times lasted between 6-158 min, with an average of 50 min., and DHCA times ranged from 0-66 min, with a mean of 19 min. The perfusion techniques used allowed patient clinical data to remain consistent throughout the cardiopulmonary bypass period, regardless of lower flows (Figure 1) The 30-day postoperative mortality rate was 2.9 %, with no evidence of neurologic injury during follow up. In conclusion, regional low flow cerebral perfusion might benefit patients by limiting the use of circulatory arrest during cardiac surgery. Further study is necessary to evaluate patient outcomes, comparing regional cerebral perfusion and circulatory arrest techniques.